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Testing IR leakage from green laser pointers

Sideburn

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Hey All,

Can you confirm that my testing for IR leakage from two green laser pointers is correct and I have no leakage?
I bought a cheap kids digital camera that seems to not have an IR filter.
I confirmed this by pointing some IR remotes at it as shown here:

Here is the camera:


camera.jpg

Heres the camera seeing the IR led from a couple remotes:

PICT0008.jpgPICT0007.jpg

here's what my test setup looks like:

testsetup.jpg


Heres what the toy (IR seeing) camera sees:

Silver laser:

PICT0012.jpg

Black Laser:

PICT0013.jpg

And here's what my iPhone (IR blocking) camera sees:


Silver laser:

greenlaser.jpg

Black laser:

blacklaser.jpg


To me it looks like there is no IR leakage from any of the photos. Do you agree?

Thanks,

-Tavis
 



Encap

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No way of telling from your photos. The green swamps out the IR + No way to tell with different cameras---apples and oranges.

The only lasers that leak IR are DPSS lasers that create green from an IR pump diode-- ie. 532nm green and the only way to tell is to block the green output-- filter out the green typically running the beam through laser a goggle/glasses lens and what remains is IR --you can measure how much IR with a laser power meter. IR in a 532nm laser is part of the same beam .

If your lasers are 520nm green they do not produce any IR. If they are 532nm then they do leak IR--how much needs to measured when the green is blocked/filtered out and only the IR gets through.
 
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Sideburn

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No way of telling from your photos.
The only lasers that leak IR are DPSS lasers that create green form an IR pump-- ie. 532nm green and the only way to tell is to block the green output-- filter out the green typically running the beam through laser a goggle/glasses lens and what remains is IR --you can measure how much IR with a laser power meter.

If your lasers are 520nm green they do not produce and IR.

they are 532nm DPSS lasers.
I was following the test shown at wired (dot) com/2010/08/laser-pointer-hazard/

I have some goggles and the camera that sees IR and I will have a laser power meter soon so I can’t try your method as well but based on the test from that page and the results I am seeing in the photos I’m not seeing any of leakage 🤔
 

Sideburn

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I ran another test aming the laser through the goggles and snapping a photo with the toy camera that can see IR light and no light is passing through:

E5867A14-D51F-4469-9C3D-FF12B91BDDCA.jpeg
 

Encap

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Who knows what that camera sees or doesn't see.
If it they are cheap 532nm lasers and don't have any internal IR filter they leak some IR --even the best expensive ones do- they all leak IR but very minimal/little if it has an internal IR filter
Check with LPM .
 
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hakzaw1

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yeah I agree.
IF you had a LPM-
you can meter the laser then place your eyewear in between the laser and LPM and meter again..

what 'passes' should be mostly IR.
OR place an IR filter between and what passes is 532. (at least in theory)
Since you never want any laser in anyone's eyes...you really have no huge need to know. AFAIK you can equate that any cheap 532 will not have a filter.. especially the 3$ 'aaa' pen pointers--
IR is not visible to most--so if your 532 quits--the last thing you need to do is look into the laser--something I think we tend to do from many years of messing common flashlights-
it quits-
we turn it on and look into the front-
then we bang it on our palm and look again... human nature.
afaik the IR spreads quickly and is not as dangerous as any visible laser.

good luck and be safe--len

Edit update-several IR filters on eekbay
this one looked good to me

$11 usd ($hip added)
 
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Sideburn

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Yeah good info. I already ordered it filters. But until I get my LPM, all I have is this cheap camera that I know can see IR fro my tests. So not perfect but reassuring.
 

hakzaw1

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I will send you a link to a member who is selling a lot of stuff--including a lpm.
 

hakzaw1

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yr very welcome
many times a member giving up the hobby and the lasers they will hang onto one LPM- just in case it is needed to complete a sale of a laser.

I am trying very hard to stop buying laser stuff...no matter how good the deal is...
Some of his stuff came via me. I trust him 100%.
He has lots of fine lasers and a few laser projectors too.
IF you buy more items he may give you a better deal or at LEAST you will save $$ on shipping vs one item at a time.
While by far NOT the cheapest--any JETLASERS laser could be a good choice. back at you soon--Len
 

paul1598419

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The best way to measure the 1064nm IR component of any DPSS laser is to use one of the inexpensive filters available on eBay and to measure with and without one of these filters. I still stock several from several years ago, but even at worst the IR component will only be up to 20% of the total power output.
 

Sideburn

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The best way to measure the 1064nm IR component of any DPSS laser is to use one of the inexpensive filters available on eBay and to measure with and without one of these filters. I still stock several from several years ago, but even at worst the IR component will only be up to 20% of the total power output.

Right, I saw those on eBay.
 




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